<template>
  <div>
    <h2>Child组件</h2>
    <button @click="handle">累加app中的count</button>
    <button @click="off">解绑</button>
  </div>
</template>

<script>
export default {
name:"Child",
methods: {
    handle(){
        this.$emit("changeCount",3)
    },
    off(){
    this.$off(["changeCount"])
    }
},
}
</script>

<style>

</style>